Not a lot people enjoy hosting or running large meetings. Despite starting out with a defined goal and a set topic for discussion, the meetings often devolve into dwelling on side issues brought up as the discussion progresses. In some ways this can be beneficial for you as an agent, because it gives you a chance to address other concerns along with the main topic of your meeting.
Certainly meetings with large groups are often fraught with ambushes along the way, but the best way to deal with a question out of the blue is to thank the individual for asking the question and ask if you can set up a personal meeting to go over those concerns. In other words, off topic questions may still lead to sales opportunities. You just have to be ready to go with the flow and recognize the opportunity to make another sale and educate another potential customer.